**Question:** Which of the following is not a feature of congenital lobar emphysema:

A. Hyperinflation of the involved lobe
B. Alveolar enlargement in the affected lobe
C. Increased respiratory effort in infancy
D. Involvement of multiple lobes

**Core Concept:** Congenital lobar emphysema (CLE) is a rare congenital lung disorder characterized by the abnormal expansion of the affected lobe or lung. This condition results from a failure of the normal developmental processes that lead to the obliteration of the bronchial tree in the affected lobe, causing the affected lobe to become trapped air sacs.

**Why the Correct Answer is Right:** D) Involvement of multiple lobes is not a feature of congenital lobar emphysema. In CLE, only one lobe or lung is affected, whereas the condition referred to as multiple lobar emphysema involves multiple lobes.

**Why Each Wrong Option is Incorrect:**

A. Hyperinflation of the involved lobe: This is a correct feature of congenital lobar emphysema, as it results in the abnormal expansion of the affected lobe due to the trapped air sacs.

B. Alveolar enlargement in the affected lobe: This is a correct feature of congenital lobar emphysema, as the trapped air sacs lead to the enlargement of the affected lobe.

C. Increased respiratory effort in infancy: Although congenital lobar emphysema may cause increased respiratory effort, this is not a universally observed feature. In some cases, infants may not exhibit increased respiratory effort due to compensatory mechanisms, such as increased chest wall motion or increased respiratory rate.

**Clinical Pearl:** Congenital lobar emphysema is typically diagnosed in the first year of life and may present with symptoms like dyspnea, respiratory distress, and tachypnea. In some cases, the condition may be discovered incidentally during imaging studies performed for unrelated reasons. Treatment options include observation, surgical intervention, or bronchopulmonary sequestration.

**Correct Answer:** D) Involvement of multiple lobes is not a feature of congenital lobar emphysema. Congenital lobar emphysema affects only one lobe or lung due to the abnormal expansion of the affected lobe caused by trapped air sacs. Multiple lobar emphysema, on the other hand, involves more than one lobe, which is not a characteristic feature of congenital lobar emphysema.